Recent stress field of the Sinai subplate region

Abstract

Quaternary and recent tectonic stress data for the Sinai subplate region have been compiled including focal mechanism solutions, in-situ stress measurements, fault slip data and alignments of young volcanic feeders. The average direction of maximum horizontal stress ( S H) has been determined by means of a linear interpolation method. The results indicate that the direction of the average maximum horizontal stress is closely parallel to the direction of the absolute motion of Africa. Analysis of the orientation of principal stress directions suggests that a large part of the Sinai subplate region is subjected to a strike-slip regime characterized by an average maximum horizontal stress trend of NW (54°W). For example, out of 50 earthquake focal mechanism solutions 52% are pure strike-slip, and 10% are either normal or thrust fault with a remarkable strike-slip component. The remaining are pure normal fault (18%), thrust fault (12%), or undetermined (8%). Three different tectonic subprovinces can be delineated. Northwestern Egypt, the eastern Mediterranean, Israel, Lebanon, and northern Syria are characterized by strike-slip often with a remarkable thrust faulting component stress regime. The northern Red Sea, the Sinai peninsula, and a significant part of the Arabian plate are characterized by strike-slip often with a remarkable normal faulting component stress regime. This is also the case for southwestern Turkey.